1918 | Taylor: Revision of the Rodent Genus Aplodontia 461 
Washington: Pierce County—Fort Steilacoom, 1; Steilacoom, 1 (skull only). 
Clallam County—Happy Lake, Olympie Mts., 6; Olympie Mts., near head of 
Soledue River (alt. 4500 ft.), 1; Port Angeles, 3. Jefferson County—Olympie 
Mts., head of north fork of Skokomish River, 2. Chehalis County—Quiniault 
Lake, 8. Mason County—Lake Cushman, 5; ‘‘Mason County,’’ 2 (odd skulls). 
Geographic Range—Northwestern Washington, vicinity of Olym- 
pic Mountains, intergrading with Aplodontia rufa rufa in the vicinity 
of Steilacoom, southern Puget Sound. 
Cranial Characters——Skull moderate in size (see measurements 
below) ; nasals tending to be somewhat variable in outline; temporal 
lnes or ridges tending to be more closely approximated anteriorly 
than in rufa; zygomatic arches tending to be lighter in weight than 
in rufa; thirteen out of seventeen crania examined with prominent 
postorbital process on the jugals, a character not developed to the 
same degree in any other form of Aplodontia; audital tubes tending 
to be of smaller caliber than in typical rufa; notch on upper side of 
external auditory meatus smaller and narrower than in typical rufa. 
External Characters—Above, 1 summer specimens, pinkish cinna- 
mon to light ochraceous-buff, often with something of a grayish cast ; 
the whole grizzled with more or less of an admixture of black hairs; 
head and face brownish or grayish; under parts grayish with a faint 
wash of pinkish buff or cinnamon buff. 
Sexual Differences—No appreciable external differences due to 
sex have been observed except in respect to the spot markings of the 
mammae and possibly a slight pallor ventrally in females. 
CRANIAL MEASUREMENTS OF Aplodontia rufa olympica (17 SKULLS) 
Average Mean Maximum Minimum 
Basilar length 2 09:3 60.2 63.0 57.4 
Length of nasals (12 skulls) . 26.4 26.9 28.9 24.9 
Wadithwotemiasallsi-e--eeeee TES 12.1 13.3 10.8 
Length of audital tube (12 skulls) - 18.9 19.1 20.0 18.1 
Length of incisive foramen. .... 7.0 7.2 8.0 6.4 
Zygomatic width (15 skulls) 54.6 54.9 56.9 52.8 
Greatest width of interpterygoid fossa (12 skulls) 5.2 5.2 6.0 4.4 
Mastoid width of cranium (16 skulls) —- ee 05.0) 52.8 55.9 49.7 
Alveolar length of superior cheek teeth 19.3 19.4 20.2 18.5 
Distance between infraorbital foramina Bee Gto 16.4 17.5 15.3 
Mandible, transversely across angular process ... 23.3 23.5 25.2 21.9 
Mandible, greatest length ...............--------------------+ 47.1 46.8 49.7 43.8 
EXTERNAL MEASUREMENTS OF Aplodontia rufa olympica (10 SKINS) 
Average Mean Maximum Minimum 
355 353 367 340 
49 47 59 36 
Total length 
Hind foot 
